A method to evaluate lodging potential in rice cultivars based on elastic stability theory

1994 ◽  
Vol 34 (7) ◽  
pp. 953 ◽  
Author(s):  
PM Moldenhauer ◽  
KAK Moldenhauer
Keyword(s):  
Plant Height ◽  
Cross Section ◽  
Modulus Of Elasticity ◽  
Elastic Stability ◽  
Elastic Behavior ◽  
Rice Cultivars ◽  
Lodging Resistance ◽  
Bending Modulus ◽  
The Difference ◽  
Panicle Weight

Physical characteristics of rice which may be used to evaluate lodging resistance have been measured or calculated. The main characteristics considered were plant height, plant cross-section properties measured by the second moment of area, and the elastic behavior of the culm measured by the bending modulus of elasticity. A method for determining the modulus of elasticity is described. Plant height, modulus of elasticity, and relative straw strength scores were compared. The concept and application of natural stability was discussed in the context of Euler column theory. Euler column theory was applied to near-harvest rice. Predicted critical loads and the difference between predicted loads and average panicle weight were compared with relative straw strength scores.

scholarly journals Agro-morphological Variation in 71 Traditional Rice Cultivars in Sri Lanka

2019 ◽  
pp. 1-16
Author(s):  
A. L. Ranawake ◽  
M. J. Hewage ◽  
N. G. J. Pradeepika ◽  
G. W. D. K. Jayasinghe
Keyword(s):  
Sri Lanka ◽  
Plant Height ◽  
Grain Weight ◽  
Total Biomass ◽  
Rice Cultivars ◽  
Panicle Length ◽  
Days To Maturity ◽  
Final Yield ◽  
Traditional Rice ◽  
Panicle Weight

Traditional rice cultivars in Sri Lanka have diverse characteristics that prove the excellent potential for utilizing them for varietal improvement. Seventy-one Sri Lankan traditional rice cultivars obtained from Plant Genetic Resources Center, Gannoruwa, Sri Lanka were used for diversity analysis. Data were collected in the middle-row-plants of each replicate and altogether 80 plants were evaluated in four replicates of each cultivar. Data were collected on 11 parameters in two consecutive Maha seasons in 2012-2014. According to the standard evaluation system of international rice research institute, 67% rice cultivars were tall, and 66% were low tillering. There was no any rice cultivar with high and good reproductive tillers/plant. Around 55% rice cultivars were partially sterile and 43% were fertile. The shortest days to maturity was recorded in Gonabaru (62 days) and the longest days to maturity was recorded in Vellainellu (105 days). The variation of agro-morphological characteristics was broad in studied rice cultivars: The recorded highest yield was 22.74 g/plant while the lowest was 1.55 g/plant. The hundred-grain-weight ranged from 3.49-1.27 g and the plant height ranged from 95-192 cm. The recorded highest number of total tillers per plant was 10 and the lowest was 3. Panicle length and panicle weight were ranged from 13-32 cm and 0.36-4.69 g consecutively. The smallest grains were in Herath and the largest grains were in Mudaliwi. The heaviest above ground biomass was achieved by Kallurundoivellai and its harvest index was the least (0.09). The highest filled grain percentage (91.48%) was recorded by Galpa Wee. The correlation analysis revealed that the yield per plant was significantly correlated with panicle weight, the total number of spikelets/panicle and number of fertile spikelets/panicle. There was no correlation between panicle length and the final yield of rice though panicle length was correlated with plant height and panicle weight. Total number of spikelets/panicle, the number of fertile spikelets/panicle, and plant height were significantly correlated with panicle weight. None of the parameters were correlated with hundred grain weight. Total biomass was correlated with plant height, the total number of spikelets, and fertile spikelets per panicle. There was no significant correlation between the biomass of rice with the final yield, however, a number of fertile tillers were correlated with a number of total tillers. Eleven parameters were sorted into four principal components that explained 87.44% of total variance and cluster analysis categorized the rice cultivars into six clusters at rescaled cluster distance 10 in Ward's linkage analysis.

scholarly journals Genome-wide association study (GWAS) to identify soybean stem pushing resistance and lodging resistance loci

2021 ◽  
Author(s):  
Shin Kato ◽  
Bahram Samanfar ◽  
Malcolm Morrison ◽  
Wubishet Bekele ◽  
Davoud Torkamaneh ◽  
...  
Keyword(s):  
Plant Height ◽  
Genome Wide Association Study ◽  
Chromosome 11 ◽  
Chromosome 5 ◽  
Eastern Canada ◽  
Lodging Resistance ◽  
Genome Wide ◽  
Glycine Max L ◽  
Plant Stem ◽  
The Difference

Lodging resistance is an important objective for soybean [Glycine max (L.) Merr.] breeding, but selection for this trait has been difficult since the resistance is controlled by multiple genes and these genes interact with the environment. One hundred thirty of 139 lines constituting a soybean GWAS panel were phenotyped for stem pushing resistance, which is defined as the push-back strength when the plant stem is inclined, by measuring the force required to push a stem to a 45° angle using a force gauge in a greenhouse, and also for lodging, plant height, seed yield and maturity at three locations in total in Eastern Canada in 2013 or 2017. Two QTLs for pushing resistance were identified, on chromosome 5 and 11, and each QTL accounted for 16.0% of phenotypic variation. In our panel, the alleles for higher pushing resistance were always of lower frequency than the alternate allele. Examining the panel at these QTLs identified that higher pushing resistance was associated with lower lodging on chromosome 5 and 11, and that the difference for lodging between alleles was significant on chromosome 5. There was no difference in plant height or yield at the QTL on chromosome 5 or 11, while higher pushing resistance was associated with later maturity at both QTLs. The pushing resistance QTL on chromosome 11 will be useful for decreasing lodging in Canadian short-season soybean.

scholarly journals Apical Extrusion of Debris Produced during Continuous Rotating and Reciprocating Motion

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Giselle Nevares ◽  
Felipe Xavier ◽  
Luciana Gominho ◽  
Flávia Cavalcanti ◽  
Marcely Cassimiro ◽  
...  
Keyword(s):  
Cross Section ◽  
Sodium Hypochlorite ◽  
Reciprocating Motion ◽  
Continuous Motion ◽  
Analytical Balance ◽  
Root Canals ◽  
Apical Extrusion ◽  
Final Weight ◽  
The Difference

This study aimed to analyse and compare apical extrusion of debris in canals instrumented with systems used in reciprocating and continuous motion. Sixty mandibular premolars were randomly divided into 3 groups (n=20): the Reciproc (REC), WaveOne (WO), and HyFlex CM (HYF) groups. One Eppendorf tube per tooth was weighed in advance on an analytical balance. The root canals were instrumented according to the manufacturer’s instructions, and standardised irrigation with 2.5% sodium hypochlorite was performed to a total volume of 9 mL. After instrumentation, the teeth were removed from the Eppendorf tubes and incubated at 37°C for 15 days to evaporate the liquid. The tubes were weighed again, and the difference between the initial and final weight was calculated to determine the weight of the debris. The data were statistically analysed using the Shapiro-Wilk, Wilcoxon, and Mann-Whitney tests (α=5%). All systems resulted in the apical extrusion of debris. Reciproc produced significantly more debris than WaveOne (p<0.05), and both systems produced a greater apical extrusion of debris than HyFlex CM (p<0.001). Cross section and motion influenced the results, despite tip standardization.

The effect of finite deformations in the elastic stability of plane frames

1962 ◽  
Vol 266 (1324) ◽  
pp. 47-67 ◽  
Keyword(s):  
Critical Load ◽  
Failure Load ◽  
Elastic Stability ◽  
Load Level ◽  
Load Factor ◽  
Proportional Loading ◽  
Arbitrary Load ◽  
Plane Frames ◽  
The Difference ◽  
Rigid Joints

The circumstances are discussed under which orthogonal relations exist between the elastic critical modes of plane frames subjected to proportional loading. Orthogonal relations may be obtained provided the loading does not produce any components of deformation associated with any of the critical modes at arbitrary levels of the load factor, and provided no part of the structure remains statically indeterminate due to bar forces when all rigid joints are replaced by pin joints. When at arbitrary load factors, the structure deforms with components associated with any of the buckling modes, the elastic failure load is not identical with the lowest elastic critical load, although for many frames the two loads may be very close. A general expression is obtained which reveals the relation between the deformations at an arbitrary load level and the deflexions given by linear analysis. The difference between the elastic failure load and the elastic critical load is discussed, and an approximate treatment applicable to certain types of frame and associated loading is developed.

Theoretical study on photoemission of double-layer AlxGa1−xAs/GaAs nanocone array photocathode

2021 ◽  
Author(s):  
Yan Sun ◽  
Lei Liu ◽  
Zhisheng Lv ◽  
Xingyue Zhangyang ◽  
Feifei Lu ◽  
...  
Keyword(s):  
Cross Section ◽  
Light Trapping ◽  
Spectral Response ◽  
Circular Cross Section ◽  
Geometrical Parameters ◽  
Internal Electric Field ◽  
Surface Emission ◽  
The Difference ◽  
Section Structure ◽  
Light Capture

In the design of photocathode, the internal electric field could be formed due to the graded Al compositional [Formula: see text] nanostructure, which can improve the top surface emission probability of carriers. In this paper, [Formula: see text] nanostructure array photocathode composed of two sub-layers is presented. Based on the finite element method, the influence of graded geometrical parameters on their optoelectronic characteristics is investigated. The results show that when the thickness of the sublayer is equal, the difference of the Al composition between the two sublayers of nanostructure is larger, the sub-layers are less, and the quantum efficiency is higher. The light capture ability of the photocathode can be enhanced by increasing the thickness and the array spacing of the first sublayer. Compared with the hexagonal cross-section structure, the light trapping effect and spectral response of the circular cross-section structure are better.

scholarly journals The Tolerance of Several Hybrid Corn (Zea mays L.) Varieties Type on Cob Rot in the Plateau of Simalungun Regency

2020 ◽  
Vol 8 (03) ◽  
pp. 289-295
Author(s):  
Warlinson Girsang ◽  
Rosmaria Girsang
Keyword(s):  
Plant Height ◽  
Zea Mays L ◽  
Block Design ◽  
Hybrid Corn ◽  
Randomized Block Design ◽  
Tolerant Variety ◽  
Different Types ◽  
The Difference ◽  
Rot Disease ◽  
Number Of Seeds

The research was carried out in Dolog Masagal Subdistrict, Simalungun Regency, altitude ± 1.100 m above sea level. The research was conducted from January to May 2019. The purpose of this study was to determine the tolerance level of several hybrid corn varieties to cob rot disease. Methods for conducting the research used randomized block design (RBD) with 1 factor. Types of hybrid corn varieties tested were: Pioneer 29 (V1), NK 99 (V2), Pioneer 12 (V3), NK 22 (V4), Pioneer 4 (V5), Nusantara I (V6), Asia 1 (V7).The parameters observed were: plant height, cob diameter, cob length containing seeds, number of seed rows per cob, number of seeds per row, number of seeds per cob,  husk cover in cob, cob rot intensity, the amount of dry production per plot, and the weight of 1.000 seeds. Based on the research results, different types of hybrid corn varieties produce different tolerances of cob rot resistance in the Simalungun highlands. The most tolerant variety of cob rot disease is Pioneer 29 (mild damage scale = 0 - 10%). Different types of varieties planted also affect various components of growth and production, among others: plant height, number of seeds per row, number of seed rows per cob, husk cover on cob, dry production per plot, and weight of 100 grains. As for the parameters of cob diameter, cob length containing seeds and the number of seed rows per cob, the difference in varieties did not significantly affect.

scholarly journals Pemilihan Karakter Agronomi untuk Seleksi pada Galur-galur Padi Dihaploid Hasil Kultur Antera

2017 ◽  
Vol 45 (1) ◽  
pp. 1-8
Author(s):  
Gerland Akhmadi ◽  
Bambang Sapta Purwoko ◽  
Iswari Saraswati Dewi ◽  
Dan Desta Wirnas
Keyword(s):  
Plant Breeding ◽  
Anther Culture ◽  
Plant Height ◽  
Plant Material ◽  
Agronomic Traits ◽  
Culture Technique ◽  
Genotypic Correlation ◽  
Agronomic Characters ◽  
Selection Of ◽  
Panicle Weight

Anther culture technique is able to accelerate plant breeding activities. The objectives of this research was to determine the agronomic traits that could be used for selection of the dihaploid rice line population through the calculation of heritability, genotypic correlation, path analysis and selecting dihaploid rice lines. The plant material used was 65 dihaploid rice lines DH 1 of F1 anther culture plants and Ciherang and Inpari 13 as check varieties. Agronomic characters that could be used as selection character are generative plant height, number of filled grain per panicle, the total number of grains per panicle, weight of 1,000 grains, and grain per hill. Twenty three dihaploid lines were selected based good agronomic characters with criteria generative plant height between 80-120 cm, number of filled grains per panicle > 100, number of grains per panicle > 120, weight of 1,000 grains > 20 g, and grain per hill > 25 g.Keywords: anther culture, heritability, agronomic characters

scholarly journals MICRO-MECHANICAL PROPERTIES OF CEMENT AND SLAG COMPOSITES MEASURED BY NANOINDENTATION

2020 ◽  
Vol 26 ◽  
pp. 45-49
Author(s):  
Jiří Němeček ◽  
Jiří Němeček
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Modulus Of Elasticity ◽  
Volume Fraction ◽  
Blended Cement ◽  
Hydration Products ◽  
Granulated Blast Furnace Slag ◽  
The Difference ◽  
Portland Cement Paste ◽  
Furnace Slag

In this study, the micromechanical response of two cementitious composites was characterized by nanoindentation. Pure Portland cement paste and Portland cement with 50 vol. % replaced with granulated blast furnace slag (GBFS) paste were investigated at the age of 28 days. Grid nanoindentation, statistical deconvolution and scanning electron microscopy were used to characterize the main hydration products. Several grids with approximately 500 indents on each sample were performed to obtain modulus of elasticity, hardness and creep indentation parameter. Similar mechanical phases containing calcium silica hydrate, crystalline calcium hydroxide and un-hydrated clinker were found in both samples varying by volume fraction. Blended cement, moreover, contains a phase of slag hydration products with a significantly lower modulus of elasticity. This phase with a high portion of unreacted GBFS is mostly responsible for the difference of mechanical properties of the whole composite.

Decomposing the Non-Gaussian Surface in Sum of Gaussian Surfaces

2012 ◽  
Vol 580 ◽  
pp. 170-174
Author(s):  
Zhang Xing Qi ◽  
Zhen Sen Wu ◽  
Zi Wen Yu ◽  
Hai Ying Li
Keyword(s):  
Cross Section ◽  
Electromagnetic Scattering ◽  
Radar Cross Section ◽  
Kirchhoff Approximation ◽  
Munk Function ◽  
The Difference ◽  
Non Gaussian ◽  
Gaussian Surface

The decomposition of the multivariate Non-Gaussian PDF in the sum of a Gaussian PDF instead of the Gram-Charlier series is investigated. Four parameters need to be found by minimizing the integrated square of the difference between Cox-Munk function and its approximation. The backscattering radar cross section (RCS) of the surface is calculated by the Kirchhoff approximation (KA) under different value of k using the formula of decomposition of the Non-Gaussian. The condition of KA satisfying electromagnetic scattering scale from Gaussian and Non-Gaussian surfaces is taken into account by computing the backscattering coefficients in HH and VV polarity.

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